Computing Ext for graph algebras
| dc.creator | Tomforde, Mark | |
| dc.date | 2001-03-08 | |
| dc.date | 2003-06-12 | |
| dc.date.accessioned | 2026-07-07T04:40:34Z | |
| dc.date.available | 2026-07-07T04:40:34Z | |
| dc.description | For a row-finite graph G with no sinks and in which every loop has an exit, we construct an isomorphism between Ext(C*(G)) and coker(A-I), where A is the vertex matrix of G. If c is the class in Ext(C*(G)) associated to a graph obtained by attaching a sink to G, then this isomorphism maps c to the class of a vector which describes how the sink was added. We conclude with an application in which we use this isomorphism to produce an example of a row-finite transitive graph with no sinks whose associated C*-algebra is not semiprojective. | |
| dc.description | 23 pages, uses XY-pic, to appear in the Journal of Operator Theory, some small typos corrected | |
| dc.identifier | https://arxiv.org/abs/math/0103055 | |
| dc.identifier | http://arxiv.org/abs/math/0103055 | |
| dc.identifier | J. Operator Theory 49 (2003), 363--387 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/61063 | |
| dc.subject | Operator Algebras | |
| dc.subject | 19K33, 46L55 | |
| dc.title | Computing Ext for graph algebras | |
| dc.type | text |